Housing retrofit assembly for a milling machine or the like

ABSTRACT

The present invention is a housing retrofit assembly for a milling machine or the like, including a quick adjusting stop nut for selective sliding coarse adjustment and rotational precision fine adjustment for rotatable engagement with a threaded rod or shaft in close tolerances, which provides stable precision engagement with the shaft, and which provides a positive locking mechanism. A unique lighting assembly is also disclosed which moves with the machine head for illuminating the milling cutter or the workpiece.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 10/653,482, filed Sep. 2, 2003 now U.S. Pat. No. 6,789,986,which claims priority from U.S. patent application Ser. No. 10/222,252,filed Aug. 16, 2002, now U.S. Pat. No. 6,612,790, and claims the benefitof U.S. Provisional Application No. 60/312,969, filed Aug. 16, 2001.

FIELD OF THE INVENTION

The present invention relates generally to attachments for machinetools. The invention concerns a housing assembly that is adapted andretrofitted for use with vertical milling machines to measure thevertical travel, or milling depth, of the quill mechanism. Moreparticularly, the invention concerns a stop mechanism for engagementwith a threaded rod, and a control mechanism for the quill.

BACKGROUND

Vertical milling machines are known in the art and a number of differenttypes of milling machines are commercially available. By way of example,Bridgeport® and RF Rong Fu® produce various models of milling machines.These commercially available milling machines are generally classifiedinto two main divisions, vertical and horizontal. In the horizontalmilling machines, the cutter is horizontally mounted to a spindle andmoves in a horizontal manner. Similarly, in a vertical milling machine,the cutter is vertically disposed and moves in a vertical fashion.

A conventional vertical milling machine generally includes a table onwhich a workpiece can be supported, and a quill that supports a tool orcutter for movement toward and away from the table for milling theworkpiece. Typically, the table is adjustable within the horizontalplane from side to side and from front to back relative to the quill.Although many milling machines are manual, in the sense that adjustmentof the table and movement of the quill is manually achieved,improvements in the art have been made for fully automated machines.These automated machines provide some advantages over manual machines,however, they are considerably more expensive for users. Moreover, theylack the versatility of manual machines.

In addition to the above, many of the manual, vertical milling machinescommercially available provide an already attached manual measuringapparatus for determining the vertical travel, or milling depth, of thequill. By way of example, RF Rong Fu® milling machines provide a plasticassembly located on the face of the machine. The assembly comprises ahousing attached to the milling machine and a moveable indicatorattached to a quill shaft stop bar. The housing further has arectangular hole which is centrally located thereon and a measurementscale surrounding the hole. As the quill is lowered and raised theindicator points to a corresponding measurement on the measurementscale, thereby informing a user of the approximate vertical movement ordepth.

A disadvantage of the current measuring devices provided in millingmachines is that they do not provide precise measurements. Typically,the units of measure on the devices are not small enough and one'sability to properly bore holes and mill workpieces is restricted. Anexample of an industry that thus is restricted is the steel industry, inwhich machined parts must be milled to precise tolerances. The measuringunits currently provided simply do not and cannot accurately measurepieces to ensure that certain hole depths meet those tolerances. Thus, aneed exists for an apparatus which provides a precise measurement of thedepth or vertical movement of a quill.

Currently, there exist some measuring devices which accurately determinethe vertical movement of the quill. However, for various reasons, thesedevices are ineffective to accomplish the objects stated herein. Forexample, the Mitutoyo Corporation manufactures the Digimatic Quill Kitfor vertical Bridgeport® milling machines and Bridgeport® type machines.The Quill Kit essentially is a retrofitted housing comprising a mainscale, a digital display indicator attached to the front surface of themain scale, a rear support plate secured to the rear of the indicator,thereby securing the indicator to the main scale, a tapped hole mountingbracket which is attached to the scale, a base, a scale stop bar that ismounted to the rear plate, a scale stop bracket and a plurality ofscrews and washers. The Quill Kit unit is attached to a milling machineby first retracting the spindle of the machine and removing the quillwheel. Vernier scale screws of the milling machine are removed and thebase is placed over the vernier scale. The vernier screws are replacedand the mounting bracket is attached to the base. The scale is attachedto the mounting bracket by the scale stop bracket.

A disadvantage of the Quill Kit is that it is only useful forBridgeport® type machines. The device simply cannot be used on othertypes of milling machines, such as the RF Rong Fu® models. Moreover, theQuill Kit is comprised of many unnecessary components. As such, it isexpensive to manufacture.

Stops and guides for use on drilling, depth milling and other similarmachinery are known, as are quick release nuts which provide forselective sliding or threading motion with respect to a threaded shaft.Guthrie U.S. Pat. No. 4,693,656 describes such devices. Current stops,as shown by Guthrie, have a spring which presses against the end of therelease nut, causing the stop to remain in place. However, sucharrangement is not sufficiently tight to prevent movement of the stop onthe threaded shaft or rod.

Thus, it is clear that a need exists for an inexpensive, stop which canhold be tightly when desired, and which can be provide both coarse andfine adjustments, and which is simple and versatile, and readilyretrofit for use with vertical milling machines, and which is readilyremovable.

SUMMARY OF THE INVENTION

The present invention is a quick adjusting stop nut for selectivesliding coarse adjustment and rotational precision fine adjustment forrotatable engagement with a threaded rod or shaft in close tolerances,which provides stable precision engagement with the shaft, and whichprovides a positive locking mechanism.

The present invention is particularly useful with a retrofit apparatusfor vertical milling machines which generally comprises a mountingcover, a main scale, an indicator, a rear plate, a plurality of hatclips, a plurality of screws, a quill stop bar, a set screw, a quillstop mount and a graduated rod. The main scale is slidably attached tothe rear of the indicator. The rear plate is connected to the rearsurface of the indicator by a plurality of screws with the scaledisplaced therebetween. The mounting cover of the present invention hasa generally rectangular configuration. Further, the mounting cover has agenerally elongated rectangular aperture, substantially and centrallylocated therein. The length of the aperture extends along the length ofthe mounting cover face. The scale, indicator, and rear plate aresecured to the face of the mounting cover by a plurality of hat clips.The components are secured so that the indicator is fixed within theaperture of the mounting cover and slidably moves in concert with thequill.

Attachment of the assembly to the quill stop bar and quill stop mount isaccomplished by screwing the rear plate to the quill stop bar andinserting the quill stop bar into an aperture in the quill stop mount. Agraduated rod is provided for connection to the quill stop mount,thereby allowing the slide support and scale to slidably move up anddown. The entire assembly is then fixed to a milling machine by aplurality of screws which are matingly inserted into a plurality ofcorresponding receiving holes located on the milling machine and theleft and right sides of the mounting cover.

In an alternative embodiment, the invented retrofit generally comprisesa mounting cover, a main scale, an indicator, a slide support, a clampmount, a plurality of hat clips, a plurality of screws, a quill stopbar, a quill stop mount and a graduated rod. The main scale is slidablyattached to the rear of the indicator. The slide support bracket isconnected to the rear surface of the scale by a plurality of hat clipsand screws which partially cover the ends of the front surface of thescale. The mounting cover of the present invention has a generallyrectangular configuration. Further, the mounting cover has a generallyrectangular aperture, having a substantially similar configuration asthe indicator, located at the bottom end of its face. The scale,indicator, and slide support are secured to the mounting cover by aclamp mount, which is disposed between the indicator and the slidesupport. The components are secured so that the indicator is fixedwithin the aperture of the mounting cover.

Attachment of the assembly to the quill stop bar and quill stop mount ofthe alternative embodiment is accomplished by screwing the slide supportto the quill stop bar and inserting the quill stop bar into an aperturein the quill stop mount. A graduated rod is provided for connection tothe quill stop mount, thereby allowing the slide support and scale toslidably move up and down. The entire assembly is then fixed to amilling machine by a plurality of screws which are matingly insertedinto a plurality of corresponding receiving holes located on the millingmachine and the left and right sides of the mounting cover.

In another alternative embodiment of the present invention, the retrofitcomprises a mounting cover, a main scale, an indicator, a rear plate, ahat clip clamp mount, a quill stop, a mount and a quill shaft. Theaperture of the mounting cover is of a corresponding size to theindicator. The main scale is slidably mounted to the indicator by therear plate. The indicator and scale are attached to the mounting coverby the clamp mount. In addition, the indicator and scale are fixed tothe quill shaft and quill stop at the mount. Subsequently, the entireassembly is joined to the milling machine by a plurality of screws whichconnect the two by a plurality of corresponding holes located on themilling machine and the left and right sides of the mounting cover.

In a further embodiment of the present invention, a second generallyelongated aperture is present along side the first aperture. The secondaperture is of a shorter length and runs parallel to the first aperture.Displaced within the second aperture is a hard stop block having aT-bolt configuration. The hard stop block has an additional lock leverwhich, when engaged allows a user to set the block along the secondaperture at a predetermined point. In operation, the user moves the hardstop block to a desired location on the second aperture and locks it inplace. Once the quill is extended, the rear plate contacts the hard stopblock and resists further extension. This feature allows the user tomill multiple workpieces at a consistent depth.

Another embodiment is shown in FIGS. 24–29, which provides for one ormore light assemblies to be focused on the milling head or theworkpiece.

OBJECTS OF THE INVENTION

Accordingly, it as a principal object of the present invention toprovide a stop nut for milling machines which accurately and tightlyholds against vertical movement of a quill during operation.

A further, and more particular, object of the invention is to provide astop nut for a threaded rod that can be adapted and retrofitted tovarious machines.

Another object of the invention is to provide a stop nut assembly whichallows measuring the precise vertical movement of a quill or otherdevice during operation, while holding tightly to prevent movementduring operation.

Another object of the invention is to provide lighting means movablewith the quill head adjacent the milling cutter.

A further object of the invention is to provide lighting means whichilluminates the workpiece, and allows for replacement of bulbs.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects will become more readily apparent byreferring to the following detailed description and the appendeddrawings in which:

FIG. 1 is a front view of a conventional vertical milling machine, butincluding a circuit breaker switch.

FIG. 2 is a fragmentary view of the milling machine shown in FIG. 1.

FIG. 3 is an isometric exploded view of a housing assembly of thepresent invention;

FIG. 4 is a side view of the invented housing assembly of FIG. 3;

FIG. 5 is a front view of the invented housing assembly of FIG. 3;

FIG. 6 is an exploded isometric view of an alternative embodiment of thehousing assembly of FIG. 3;

FIG. 7 is a side view of the alternative embodiment of the housingassembly of FIG. 6;

FIG. 8 is a front view of the alternative embodiment of the housingassembly of FIG. 6;

FIG. 9 is an exploded isometric view of another alternative embodimentof the housing assembly of FIG. 3;

FIG. 10 is a side view of the alternative embodiment of the housingassembly of FIG. 9;

FIG. 11 is a front view of the alternative embodiment of the housingassembly of FIG. 9.

FIG. 12 is a side view of a further alternative embodiment of thehousing assembly of FIG. 3.

FIG. 13 is a fragmentary side view of the alternative embodiment of thehousing assembly of FIG. 12.

FIG. 14 is an exploded isometric view of the alternative embodiment ofthe housing assembly of FIG. 12.

FIG. 15 is a cross-sectional view of the invented stop nut assembly.

FIG. 16 is a partially cutaway view of the stop nut assembly of FIG. 15.

FIG. 17 is a cross-sectional view of the stop assembly showing a stopmechanism.

FIG. 18 is a schematic right side view of the stop assembly of FIG. 15.

FIG. 19 is a cross-sectional view of the invented stop assembly of FIG.15 showing an alternative spring biasing means.

FIG. 20 is a left side view of the spring of FIG. 19.

FIG. 21 is shows the offsets of the two bores in the plunger.

FIG. 22 is a partial view of a milling machine showing the stop nutassembly installed thereon.

FIG. 23 is a partially sectioned side view of FIG. 22.

FIG. 24 is a partially cutaway front view of a milling machine showinganother alternative embodiment of a retrofit assembly.

FIG. 25 is side view of the embodiment of FIG. 24.

FIG. 26 is a side view of a milling machine incorporating the embodimentof FIGS. 24 and 25 therein.

FIG. 27 is a cross-sectional view of an alternative light assembly,which is readily adaptable to a quill in accordance with the invention.

FIG. 28 is a front view of a light switch assembly mounted on a quillfor activating one or more lights of a light assembly.

FIG. 29 is a cross sectional view of the light switch assembly takenalong line A—A.

DETAILED DESCRIPTION

Referring now to the drawings, a conventional vertical milling machine100 is shown in FIGS. 1 and 2, and generally includes a frame presentinga table 112 and a quill head 114 overlying the table 112, and a quill116 supported on the head 114 for rotation and for relative shiftablemovement along a central longitudinal axis thereof toward and away fromthe table 112 between retracted and extended positions.

The frame includes an upstanding column 118 which supports the quill 116and head 114, and a knuckle (not shown) supported on the column 118 forpivotal movement about a transverse, horizontally extending shaft (notshown). The knuckle is secured in place relative to the column 118 by aplurality of bolts which can be loosened to enable orientation of theknuckle to be adjusted about the shaft. The head 114, in turn, ismounted on the knuckle for pivotal movement about a horizontal axis thatis perpendicular to the axis of the shaft. Angular adjustment of thequill 116 about the X and Y axes can be achieved in order to orient thequill 116 at any desired angle relative to the table 112.

A motor 120 is mounted on the head 114 for driving rotation of the quill116, and a manual feed lever 122 is connected to the quill 116 through arack and pinion quill feed transmission so that when the lever 112 isshifted, the quill 116 is moved between the retracted and extendedpositions. The motor 120 is connected to the quill 116 through asuitable transmission arrangement for automatically extending the quill116 when the transmission is engaged. The feed transmission arrangementincludes a quill feed engagement control lever 124 that protrudes from aboss on the right side of the quill head 114 for permitting an operatorto engage and disengage the feed transmission, as desired. A cover isnormally held in place over the quill head 114 that can be removed toallow access to the transmission components within the head 114.

The feed transmission of the motor 120 includes a feed kick-outmechanism for disconnecting the quill 116 from the feed drive of themotor 120 when the quill 116 has been extended by a distance preset bythe user. The feed kick-out mechanism includes a depth stop screw (notshown) supported between the quill head 114, a depth stop block receivedaround a stop screw (not shown) and the quill 116. A travel stop ring126 is threaded onto the stop screw for adjustment along the lengththereof. When the quill feed engagement control lever 124 is moved tothe engaged position, the quill 116 is moved automatically toward theextended position by the motor 120 and the depth stop block travelsalong the depth stop screw until the block engages the travel stop ring126. The force of the stop block against the ring 126 trips theengagement lever 124 and the feed transmission between the motor 120 andthe quill 116 is disconnected.

A scale box 128 is centrally mounted over the quill head 114 with amanual scale 130 disposed therein to allow a machinist to gauge thedepth of the quill 114, and to set the position of the travel stop ring126 so that drive to the quill 114 is disconnected at the desired depth.The scale box 128 has a generally elongated rectangular aperture forreceiving the scale 130. The scale box 128 is fixed to the millingmachine 100 at predetermined connection points 132. The connectionpoints 132 are preferably threaded holes located in the milling machine100 and are adapted to receive screws which secure the scale box 128 inplace.

The vertical milling machine thus far described is a conventional kneemill, e.g. of the type manufactured by RongFu Corporation. Similarmachines are made by several other manufacturers around the world, suchas Bridgeport®, and the housing retrofit of the present invention can beadapted for use on any of these conventional machines without departingfrom the scope of the present invention. FIGS. 1 and 2 show animprovement to the conventional machines whereby a two-way or three-waycircuit breaker switch 70 is provided for activating and deactivatingthe machine.

FIGS. 3–5 show a preferred embodiment of the invented retrofit apparatus10. The retrofit apparatus 10 generally comprises a mounting cover orhousing 12 having a generally rectangular face configuration, a mainscale 14, an indicator 16, a rear indicator plate 18, a plurality of hatclips 20, a plurality of screws 22, a cylindrical quill stop bar 24, aquill stop mount 26 which is adapted to receive the quill stop bar 24, aset screw 28, and a cylindrical graduated rod 30.

The included indicator 16 is a digital displacement indicator. Anexample of the indicator is such as that produced by the MitutoyoCorporation for indicating the depth of holes, slots and countersinks.The indicator 16 generally includes an indicator head having a digitalreadout 32 and a plurality of control buttons 34. The indicator 16further includes an attachment means whereby it can be secured to themain scale 14 by attachment screws (not shown). While the MitutoyoCorporation device is stated as an exemplary model which may be used inthe present invention, other suitable digital displacement indicatorsmay be used.

The mounting cover 12 is preferably made of aluminum or steel and has aleft side 36, a right side 38, a face 40, a top end 42 and a bottom end44. The mounting cover 12 may be made of other suitable materials whichcan accomplish the objects stated herein. Further, the face 40 of themounting cover 12 has a generally rectangular aperture 46 locatedtherein. The aperture 46 of the face 40 has a width corresponding tothat of the indicator 16. However, the length of the aperture 46substantially extends to the top and bottom ends 42 and 44 of themounting cover 12, thereby allowing the indicator 16 to slidably movealong the scale 14. Located on the mounting cover's left and rightsides, 36 and 38 respectively, are attachment notches 48 for attachingthe retrofit apparatus 10 to a milling machine 100.

The main scale 14 has a generally elongated rectangular configurationand is formed so that the indicator 16 can be slidably mounted thereto.The scale 14 is secured to the outer surface of face 40 of the mountingcover 12 by the plurality of hat clips 20. Further still, the indicator16 is slidably mounted to the scale 14 by the rear plate 18. Attached tothe rear plate 18 at one end is the quill stop bar 24 which is matinglyengaged with the quill stop mount 26 at its opposing end. The quill stopmount 26 is adapted to receive the cylindrical graduated rod 30.

After the scale 14 and indicator 16 are attached to the mounting cover12, they are attached to the quill stop bar 24 via the rear plate 18.The quill stop bar 24 is, in turn, matingly connected to the quill stopmount 26 at the upper end of its front surface. The quill stop bar 24 issecured in place by the set screw 28 which is received in an angularcavity located on the stop bar 24. The graduated rod 30 is also matinglyconnected to the quill stop mount 26 at its bottom surface. The retrofitapparatus 10 is fixed to the milling machine 100 by a plurality ofscrews (not shown) which connect the two by predetermined connectionpoints 132 located on the milling machine 100 and the left and rightsides, 36 and 38, of the mounting cover 12. A mounting slot 72 may beprovided in mounting cover 12 at any convenient or desired location forreceiving an mounting a light 74 thereto. The light is preferably aflexible extended light or flexible neck light, so that it can bedirected toward the work. When the quill moves up or down, light 74moves with it.

An alternative light assembly 220 is shown in FIG. 27. The lightassembly has a power source shown as a flexible wire 224 in a flexibletubing (known as a “flex-stay” tubing) which is connected to a switch226 in a switch assembly 222 which is mounted on the quill 116. Thelight assembly 220 has an interior housing 228 containing a bulbreceptacle 230 for accommodating one or more light emitting diodes 232(LEDs), referred to hereinafter as LEDs or bulbs. An exterior housing234 surrounds the interior housing and the bulb receptacle. A parabolicreflector 236 is advantageously positioned within the exterior housingfor directing the light from the bulb. The end 240 of the exteriorhousing from the which the light is emitted has a tempered glass cover242 to protect a lens, the cover being resistant to scratching. Afocusing lens 244 is mounted within the housing 234, beneath and spacedfrom the cover. The lens 244 is preferably glass or plastic, but couldbe any other desired material, such as quartz or mica. A rubber orneoprene separator 246 between the lens and the cover acts as a washeror seal to waterproof the light housing, and prevent water, oil, or anyother liquid from entering the light assembly. The cover 242 is held inplace against the seal 246 by a retainer 248 such as a spring-typeretaining ring.

The external tubular housing 234 is removable from the light assembly,and is held in place by any convenient means such as setscrew 250. Theexternal tubular housing 234 is preferably metal, such as aluminum orsteel, or alternatively made of high impact plastic. Removal of theexternal housing allows access to the bulb 232 and replacement of thebulb when it burns out.

Wire 260 leading to the light housing is coiled as shown within thequill housing, to allow movement of the light assembly with the quill116. Between the quill housing and the light housing, the wire isencased in flexible tubing, which allows it to be positioned, and tohold any desired position. The LED lamp works off of 120v, 220/240v, or440/480v single phase and 3-phase that is convertible to 24v or lessdirect current without the use of batteries. A transformer accomplishesthe voltage conversion.

Being affixed directly onto the quill 116 through a transition fitting258, the LED lamp continuously brightens the work area of the machinetools and surface of the part being machined by being properly directed.The light moves up and down with the machine tool.

The flexible tubing with the associated LED lamp gives the machineoperator a large range of area for focusing the lamp beam onto themachine surface, workpiece, and tool. For the LED, the voltage must beconverted to 12–24 volts. The higher voltage provides a brighter light.

The following voltages are commonly used with milling machines, and thepresent invention is adaptable to be used with any of them:

-   -   120 V AC-3 phase    -   120 V AC-single phase    -   220/240 V AC-single phase    -   220/240 V AC-3 phase    -   440/480 V AC-3 phase

In operation, as a drill feed control lever 124 on the milling machine100 is actuated, the quill 116 is vertically lowered to a workpiece onthe table 112 and the indicator 16 positively and precisely measures thevertical travel, or depth, of the movement and digitally displays theunit of measure. Once the quill 116 is lowered to a predetermined depthlimit, the quill stop bar 24 prevents further downward movement.

Referring to FIGS. 6–8, an alternative embodiment of the retrofitapparatus 10 is shown. The retrofit 10 comprises a mounting cover 12having a left side 36, a right side 38, a face 40, a top end 42 and abottom end 44. Again, the mounting cover 12 has a generally rectangularconfiguration and is preferably comprised of aluminum or steel. However,other, similar materials may be employed. Further, the face 40 has agenerally rectangular aperture 46 located at the bottom end 44 of themounting cover 12. The retrofit 10 further comprises a main scale 14, anindicator 16, a hat clip clamp mount 50, a cylindrical quill stop 24,and a stop mount 26. The aperture 46 in face 40 is of a correspondingsize to the indicator 16.

Similar to the first embodiment, the main scale 14 is a generallyrectangular device formed so that the indicator 16 can be slidablymounted to the front surface thereof. The indicator 16 is slidablyattached to the scale 14 and held in place by the hat clip mount 50. Theindicator 16 and scale 14 are attached to the mounting cover 12. Inaddition, the upper end of the scale 14 is fixed to the front surface ofthe quill stop bar 24 by a face mount 52. Preferably, the face mount 52is attached to the quill stop bar 24 by a screw, however, it will beappreciated that other attaching devices may be used. Again, the quillstop bar 24 is held in place by the set screw 28.

Subsequently, the entire retrofit assembly 10 is joined to the millingmachine 100 by a plurality of screws which connect the connection points132 located on the milling machine 100 and the notches 48 of the leftand right sides, 36 and 38 respectively, of the mounting cover 12.

Another alternative embodiment of the retrofit 10 is shown in FIGS. 7through 9. In this alternative embodiment, the retrofit apparatus 10comprises a mounting cover 12 having a generally rectangularconfiguration, a main scale 14, an indicator 16, a slide support 56, aclamp mount 54, a plurality of hat clips 20, a plurality of screws 22, acylindrical quill stop bar 24, a quill stop mount 26 which is adapted toreceive the quill stop bar 24 and a cylindrical graduated rod 30.

Again, the indicator 16 generally includes an indicator head having adigital readout 32 and a plurality of control buttons 34. The indicator16 further includes an attachment means whereby it can be secured to themain scale 14 by attachment screws. Further, the mounting cover 12generally has a left side 36, a right side 38, a face 40, a top end 42and a bottom end 44. The face 40 of the mounting cover 12 has agenerally rectangular aperture 46 located toward the bottom end 44. Theaperture 46 in the face 40 is of a corresponding size to the indicator16. Located on the left and right sides, 36 and 38 respectively, areattachment notches 48 for attaching the retrofit apparatus 10 to themilling machine 100.

The main scale 14 has a generally rectangular configuration and isformed so that the indicator 16 can be slidably mounted thereto. Theslide support 56 has a substantially hat clip configuration and has acorresponding length to the scale 14. However, the slide support 56 hasa greater width than the scale 14, thus allowing the scale 14 andindicator 16 to be fixed thereto by the plurality of hat clips 20 andscrews 22. Disposed between the slide support 56 and the indicator 16 isthe clamp mount 54. The indicator 16, scale 14, and slide support 56 areattached to the mounting cover 12 by the clamp mount 54 so that theindicator 16 is fixed within the aperture 46 of the mounting cover 12.

After the scale 14 and indicator 16 are attached to the mounting cover12, they are attached to the quill stop bar 24. The quill stop bar 24is, in turn, matingly connected to the quill stop mount 26 at the upperend of its front surface. The graduated rod 30 is also matinglyconnected to the quill stop mount 26 at its bottom surface. The retrofitapparatus 10 is then fixed to the milling machine 100 in the mannerpreviously described.

Referring to FIGS. 12–14, another embodiment of the present invention isshown. In this embodiment, a second generally elongated aperture 58 ispresent along side the aperture 46. The second aperture 58 is of ashorter length and runs parallel to the aperture 46. Displaced withinthe second aperture 58 is a hard stop block 60 having a T-boltconfiguration. The hard stop block 60 has an additional lock lever 62which, when engaged allows a user to set the block 60 along the secondaperture 58 at a predetermined point. In operation, the user moves thehard stop block 60 to a desired location on the second aperture 58 andlocks it in place by engaging the lock lever 62. Once the quill 116 isextended, the rear plate 18 contacts the hard stop block 60 and resistsfurther extension. This feature allows the user to mill multipleworkpieces at a consistent depth.

FIGS. 22 and 23 show sliding stop plate 200 attached to the digitalindicator, and fixed plate 202. Finished cap nut bushing 206 isinstalled at the end of the quill. The digital displacement indicator 16is mounted on a mounting plate 204 which transmits motion around thethreaded rod to which the stop nut 150 is connected. While one end ofthe threaded rod is firmly attached to a fixed mount 202 attached to thecover, the motion of the digital displacement indicator can be stoppedor adjusted with the stop nut 150. Mounting plate 204 is of sufficientlength to overlap both ends of the indicator 16 and provide protectionthereto from damage.

The invented quick adjusting nut 150 includes a nut body 152, adepressable plunger 154, and a biasing mechanism, such as a compressionspring 156.

As best seen in FIGS. 15 and 16, nut body 152 includes an axial bore orpassageway 158 adapted to receive a threaded rod or shaft 160. Axialbore 158 is suitably centrally located through nut body 152. Inaddition, a transverse bore or socket 164 extends radially inward fromone exterior point across the diameter of nut body 152 communicatingwith axial bore 158 and terminating at an end 166 in the opposite halfof body 152 beyond the axial bore. Socket 164 may have a tapered end166, as shown in FIG. 15, or it may have a flat end.

Nut body 152 may include a knurled end portion 168 for easy handling.The nut body 152 can also be provided with an upper graduated portion170, including any desired number of precision graduations.

Axial bore 158 is centrally disposed, extending through the nut body152. The diameter of axial bore 158 is selected to closely receive rod160, permitting sliding in an axial direction, but relatively littlelateral motion.

Plunger 154 is adapted to be slidably received in transverse bore 164,and has an outer end 172 accessible from the body exterior. Plunger 154includes a transverse aperture 174 defined by two slightly offset bores176 and 178 (see FIG. 21). Unthreaded bore 176 is disposed nearest theend 172 of plunger 154, and is of a larger diameter than bore 178. It issuitably of slightly larger diameter than nut body axial bore 158 (e.g.,0.505 to 0.510 inch diameter). Smaller bore 178 is suitably offset frombore 176 by approximately 0.085 to 0.075 inch, and is of a diametercommensurate with that of threaded rod 160, and is threaded in a mannersuitable for threaded engagement or mating with the threads of rod 160.

Plunger 154 is received in nut body transverse bore 164 so that aperture174 is in general registry with nut body axial bore 158. Nut body axialbore 158 and plunger aperture 174 are adapted to cooperatively receivethreaded rod 160. Biasing means such as spring 156 is placed in theterminal end 166 of nut body transverse bore 164 so that the compressivespring forces will operate in the axial direction of nut body transversebore 164, and, in the absence of external compressive force, will pushthreaded bore 178 into threaded engagement with rod 160.

The quick adjusting nut 150 is easily placed in an operative conditionon rod 160. The nut is assembled, plunger 154 is depressed, and the nut150 is mounted onto threaded rod 160 by sliding rod 160 through nut bodyaxial bore 158 and plunger aperture 174.

Coarse positioning of nut 150 is quickly and efficiently achieved bydepressing plunger 154 to release the nut, and axially sliding nut 150to the approximate desired location on rod 160, as determined by visualcoordination with machine mounted scale 21. More particularly,depressing plunger 154 inwardly in a radial direction compresses spring156, and displaces plunger aperture 174 from the spring biased (engaged)position with respect to rod 160. Rod 160 is thus disengaged fromthreaded bore 178 and is received in the larger diameter bore 176 ofplunger aperture 174 to permit the axial sliding of nut 150 with respectto the threaded rod or shaft 160. Plunger 154 is then released, wherebyspring 156 biases the smaller threaded bore 178 of the plunger aperture174 into threaded engagement with the threads of rod 160.

Plunger aperture 174 is formed with offset bores 176 and 178 ofdiffering diameters. By using a smaller threaded bore of a diametercorresponding to that of rod 160, nearly a full 180 degrees of threadedengagement between nut 150 and rod 160 is provided during threadengagement. Further, the relatively close reception of rod 160 by nutaxial bore 158, and the extended length of the axial bore help toeffectuate a secure threaded engagement.

Final securing of the stop nut 150 is by a set screw 182 which extendsthrough the face 180 of the nut body 152. A cooperating recess 184,which is preferably conical is provided in the plunger. The set screwpresses against the edge of the conical recess farthest from the springin a cam-type action, effectively tightening the clamping effect of thethreads of bore 178 of the plunger against the threads of the rod 160.This has been found to be sufficiently tight to prevent movement of thenut under all normal operating conditions.

A slot 186 of lesser depth than the recess 184 is advantageouslypositioned in plunger 154 adjacent to and communicating with recess 184to allow longitudinal movement of the plunger without complete removalof the set screw 182.

Any biasing means can be substituted for spring 156. A suitable biasingmeans is a leaf spring 190 as shown in FIGS. 19 and 20. Note that thisrequires a slight modification to the spring so that it will fit intothe bore 152. Advantageously, the leaf spring is welded to the end ofthe plunger.

Precision adjustment is achieved by rotating the nut 150 about rod 160as desired, and is facilitated by graduation portion 170 of nut body152.

The nut is shown as round in FIG. 16, however, it can have a generallysquare or hexagonal configuration, if desired.

The set screw 182 can have a knurled head for hand tightening, or it canhave a recessed head for an Allen wrench, or it can have a square orhexagonal head for engagement by a mating wrench.

The stop nut can be made of any desired material, including steel,stainless steel, brass, or aluminum. If steel, it can be black oxide orphosphate coated. If aluminum, it can be anodized, and can be made indifferent colors. If brass, it can be copper plated or chrome plated.

It should be appreciated that the present invention provides aparticularly useful device. For example, when used in a machine shopwherein about 20 quick stop adjustments are required per day, a nut 150in accordance with the present invention will save several man hours permonth, as compared to conventional adjustment mechanisms. Further, avery tight and secure engagement between nut 150 and rod 160 isprovided, which is not susceptible to undesired slippage due tovibration, nor is it susceptible to jamming.

A rotary cam selector switch 270, available from BACO Controls, Inc., ofCazenovia, N.Y., is provided at or near the top of the retrofitassembly. This three-way switch provides Forward, Reverse, and Offsettings on the same switch, which is small and compact. Most motors donot have a motor switch, but need a power switch to control the power tothe motor switch. A pilot switch can be used where the motor has a motorswitch. The 3-way switch 270 allows all of the current to move throughit without requiring a motor switch. The advantage is that it is notnecessary to modify the digital quill system to use different switchesor different motors. For instance, in the invented system, a mill drillcan use a 1 horsepower, a 1.5 HP, or a 2 HP motor without changing theswitch.

While the present invention is described in connection with millingmachines, it has advantageous application with other machines such asdrill presses, and on any threaded drive where it is desired to stopmotion precisely.

SUMMARY OF THE ACHIEVEMENT OF THE OBJECTS OF THE INVENTION

From the foregoing, it is readily apparent that I have invented aretrofit apparatus for economically measuring the vertical movement of aquill during operation, as well as a stop nut for milling machines whichaccurately and tightly holds against vertical movement of a quill duringoperation, which stop nut can be adapted and retrofitted to variousmachines having a threaded drive where it is desired to stop motionprecisely.

It is to be understood that the foregoing description and specificembodiments are merely illustrative of the best mode of the inventionand the principles thereof, and that various modifications and additionsmay be made to the apparatus by those skilled in the art, withoutdeparting from the spirit and scope of this invention, which istherefore understood to be limited only by the scope of the appendedclaims.

1. A retrofit apparatus for measuring the vertical displacement of aquill on a milling machine having: a main scale slidably mounted to anindicator, said indicator being capable of displaying the verticaldisplacement of the quill of the milling machine; a mounting coverhaving a generally rectangular configuration and an aperture locatedtherein for receiving said indicator; a stop bar fixedly secured to saidscale by an attachment means; said quill having a quill shaft attachedthereto; said quill shaft being matingly engaged to said stop bar by aquill mount; and wherein the quill shaft moves vertically responsive toa force placed thereon, thereby causing said scale to slide up and downalong the indicator; a stop nut assembly for a threaded rod, comprising:a nut body having a face and an axial bore therethrough adapted toreceive a threaded rod, said nut body being provided with a transversebore terminating in a bore end within said nut body; biasing meanspositioned in the bore end; a plunger positioned in said bore againstsaid biasing means, said plunger being provided with a rod receivingaperture, said aperture being threaded on one side only; a set screwpositioned in said face parallel to said axial bore; said plunger havinga conical recess adapted to engage said set screw; whereby tightening ofsaid set screw will force said threaded portion of said aperture tightlyagainst said threaded rod, and prevent movement thereof.
 2. A retrofitapparatus according to claim 1, further comprising a mounting plate onwhich said indicator is mounted, said mounting plate being of sufficientlength to overlap both ends of said indicator, whereby said indicator isprotected from damage.
 3. A housing retrofit assembly for use on amilling machine, wherein the milling machine includes a frame presentinga quill head, a quill supported on the head for rotation and forselective movement along a generally vertical axis between retracted andextended positions, and a manually actuated lever supported on the headand operatively connected to the quill for moving the quill between theretracted and extended positions, the assembly comprising: a mountingcover having an elongated, centrally located aperture; a scale slidablymounted to the mounting cover; an indicator for measuring thedisplacement of the quill as the quill is moved between the retractedand extended positions, the indicator providing a digital reading of thevertical displacement of the quill from a starting position; a slidesupport for attachment to said scale having a plurality of holes locatedon opposing ends of said support thereby enabling connection to a quillstop bar, said stop bar having a cylindrical configuration and beingadapted to be fixed to the support at one end and be matingly engaged toa quill stop mount at an opposing end; a clamp mount disposed betweensaid support and said scale, wherein said clamp mount is attached to themounting cover by an attachment means; a cylindrical graduated rod whichis matingly secured to the quill stop mount, wherein said graduated rodvertically moves responsive to the movement of a quill device therebycausing the scale to slidably move along the indicator; and a two-way orthree-way circuit breaker switch for activating and deactivating themachine.
 4. A housing retrofit assembly for use on a milling machine,wherein the milling machine includes a frame presenting a quill head, aquill supported on the head for rotation and for selective movementalong a generally vertical axis between retracted and extendedpositions, and a manually actuated lever supported on the head andoperatively connected to the quill for moving the quill between theretracted and extended positions, the assembly comprising: a mountingcover having an elongated, centrally located aperture; a scale slidablymounted to the mounting cover; an indicator for measuring thedisplacement of the quill as the quill is moved between the retractedand extended positions, the indicator providing a digital reading of thevertical displacement of the quill from a starting position; a slidesupport for attachment to said scale having a plurality of holes locatedon opposing ends of said support thereby enabling connection to a quillstop bar, said stop bar having a cylindrical configuration and beingadapted to be fixed to the support at one end and be matingly engaged toa quill stop mount at an opposing end; a clamp mount disposed betweensaid support and said scale, wherein said clamp mount is attached to themounting cover by an attachment means; a cylindrical graduated rod whichis matingly secured to the quill stop mount, wherein said graduated rodvertically moves responsive to the movement of a quill device therebycausing the scale to slidably move along the indicator; and means formounting a light onto said mounting cover.
 5. A housing retrofitassembly according to claim 4, further comprising a light mounted onsaid cover.
 6. A housing retrofit assembly according to claim 4 whereinsaid light is a flexible extended light movable with said quill.
 7. Ahousing retrofit assembly for use on a milling machine, wherein themilling machine includes a frame presenting a quill head, a quillsupported on the head for rotation and for selective movement along agenerally vertical axis between retracted and extended positions, and amanually actuated lever supported on the head and operatively connectedto the quill for moving the quill between the retracted and extendedpositions, the assembly comprising: a mounting cover having anelongated, centrally located aperture; a scale slidably mounted to themounting cover; an indicator for measuring the displacement of the quillas the quill is moved between the retracted and extended positions, theindicator providing a digital reading of the vertical displacement ofthe quill from a starting position; a slide support for attachment tosaid scale having a plurality of holes located on opposing ends of saidsupport thereby enabling connection to a quill stop bar, said stop barhaving a cylindrical configuration and being adapted to be fixed to thesupport at one end and be matingly engaged to a quill stop mount at anopposing end; a clamp mount disposed between said support and saidscale, wherein said clamp mount is attached to the mounting cover by anattachment means; a cylindrical graduated rod which is matingly securedto the quill stop mount, wherein said graduated rod vertically movesresponsive to the movement of a quill device thereby causing the scaleto slidably move along the indicator; a motor operatively connected tosaid quill; and a three-position rotary cam switch connected to andcontrolling said motor.
 8. A housing retrofit assembly according toclaim 7, further comprising a light assembly associated with said quillhead, and having a light switch mounted on said quill head.
 9. A housingretrofit assembly according to claim 8, wherein the light assembly has apower cord partially housed in said quill housing, said power cordhaving a coiled portion within said quill housing, which allows it toextend and retract as the light assembly moves with the quill head.